HMG1 and 2: architectural DNA-binding proteins

Biochem Soc Trans. 2001 Aug;29(Pt 4):395-401. doi: 10.1042/bst0290395.


HMG1 and 2 (high mobility group proteins 1 and 2; renamed HMGB1 and 2) contain two DNA-binding HMG-box domains (A and B) and a long acidic C-terminal domain. They bind DNA without sequence specificity, but have a high affinity for bent or distorted DNA, and bend linear DNA. The individual A and B boxes (which, although broadly similar, show both structural and functional differences) exhibit many of the structure-specific properties of the whole protein. The acidic tail modulates the affinity of the tandem HMG boxes in HMG1 and 2 for a variety of DNA targets, including four-way junctions, but not distorted DNA minicircles, to which the proteins bind with very high affinity. HMG1 and 2 appear to play important architectural roles in the assembly of nucleoprotein complexes in a variety of biological processes, for example V(D)J recombination, the initiation of transcription, and DNA repair.

Publication types

  • Review

MeSH terms

  • Binding Sites
  • DNA / chemistry
  • DNA / metabolism*
  • DNA Nucleotidyltransferases / metabolism
  • DNA Repair
  • DNA-Binding Proteins / metabolism*
  • HMGB1 Protein / metabolism*
  • HMGB2 Protein / metabolism*
  • High Mobility Group Proteins / metabolism
  • Nucleic Acid Conformation
  • Recombination, Genetic
  • Substrate Specificity
  • Transcription, Genetic
  • VDJ Recombinases


  • DNA-Binding Proteins
  • HMGB1 Protein
  • HMGB2 Protein
  • High Mobility Group Proteins
  • DNA
  • DNA Nucleotidyltransferases
  • VDJ Recombinases